Summary: Optimal Beamforming
In the previous section we looked at how fixed beamforming yields significant gains in communi-
cation system performance. In that case the beamforming was fixed in the sense that the weights
that multiplied the signals at each element were fixed (they did not depend on the received data).
We now allow these weights to change or adapt, depending on the received data to achieve a certain
goal. In particular, we will try to adapt these weights to suppress interference. The interference
arises due to the fact that the antenna might be serving multiple users.
Figure 1: A general beamforming system.
2 Array Weights and the Weighted Response
Figure 1 illustrates the receive beamforming concept. The signal from each element (xn) is multi-
plied with a weight w